Manufacture of keto-alcohol



. Knunjanz et al.

Patented Sept. 19, 1944 MANUFACTURE OF KETO-ALCOHOL ACETATES FranzBergel, Welwyn Garden City, England, as-

signor to Roche Products Limited, Welwyn Garden City, Hertfordshire,England No Drawing. Application April 30, 1942, Serial No. 441,133. InGreat Britain May 13, 1941:

3 Claims. .(Cl. 260-488) This invention relates to the manufacture ofketo-alcohol acetates. The preparation of ketoalcohol esters, such as'ys-acetopropyl alcohol acetate, is described by A. Lipp (Ber. de-rdeutschen Chem. Ges., 1899, 22, 1205), by a process in which'y-acetopropyl alcohol is treated with acetic anhydride. A simplesynthesis of 'y-acetopropyl alcohol by hydrolysis and decarboxylation ofuaceto-y-butyrolactone was described by I. L. -(Compt. rend. Acad. Sci.U. S. S. R, 1934, 1, 312), r

The present invention provides a process wherein lactones of the generalformula:

R.CO.CHOO

0 OHz-CH:

wherein R is an alkyl, aralkyl or aryl group (hereinafter referred to aslactones of the type of ozaceto-v-butyrolactone) are transformed in onestep into the acetate of the corresponding alcohol. It has been foundthat when lactones of the above type are heated with glacial acetic acidin the presence of anhydrous sodium acetate or sodium acetate containingacetic acid of crystallisation, ring opening, decarboxylation andacetyla tion all occur at the same time. If the lactones are treatedwith glacial acetic acid alone, or with a mixture of glacial acetic acidand acetic anhydride, the yield of keto-alcohol acetates is very poorindeed compared with the yield obtained when the reaction is carried outin the presence of sodium acetate.

The following examples illustrate how the process of the invention maybe carried into efiect:

1. 100 parts by Weight of u-aceto-y-butyrolactone are mixed with 300parts by weight of glacial acetic acid. 128 parts by weight of anhydroussodium acetate are added and the mixture, which gradually form ahomogeneous liquid, is refluxed for 18 to 24 hours. The still warmmixture after refluxing is poured into 450 parts by weight of benzenewith stirring and after cooling to about C. the sodium acetate withglacial acetic acid of crystallisation is filtered off. The crystals,which are well pressed on the filter, are washed with about 100 parts byweight of benzen and amount after drying over paraffin in vacuo for 1hour to about 280-300 parts by weight.

The filtered solution, after remova1 of benzene and glacial acetic acidby evaporation, is subjected to fractional distillation when'y-acetopropyl acetate boils at:

sac-99 c./12 mm. s 103-104 c. 14 mm, -112 c*./17 mm.

Th refractive index of the -acetopropyl acetate is nn =1.426.

Analysis: Found: C=58.8%, H=8.5%.

requires: C=58.3%, H=8.3%.

2. If instead of anhydrous sodium acetate sodium acetate containingacetic acid of crystallisation obtained in the course of the operationsdescribed in Example 1 is used, the following procedure is carried out:

The first step is to determine the content of glacial acetic acid in thesodium acetate, which is usually about 2 mols. (59.4%). Then, for 100parts by weight of a-aceto- -butyrolactone 112.7 parts by weight ofglacial acetic acid, and 315.3 parts of sodium acetate containing aceticacid of crystallisation are needed if the salt contains 2 mols. ofacetic acid. If'it contains less than 2 mols. the quantities of salt andglacial acetic acid added are such that the original 128 and 300 partsrespectively are present. The process is otherwise carried out asdescribed in Example 1.

3. 2 parts of a-benzoyl-'y-butyrolactone, [prepared from ethyl benzoylacetate (cf. Beilstein, X, page 674) analogous to the method by I. L.Knunjanz et al. (100. cit.) for acetobutyrolactone, boiling point about180 C./2.5 mms. (Analysis: Found: C, 69.0; H, 5.5; C11H1o03 requires: C,69.5; H, 5.3%.) 6 parts of glacial acetic acid and 1.82 parts ofanhydrous sodium acetate are mixed and refluxed for 18 hours. The stillwarm mixture is then poured into 30 parts by volume of benzene, andafter cooling to 5-10 C. the sodium acetate with acetic acid ofcrystallisation is filtered off. The filtrate after removal of benzeneand glacial acetic acid is subjected to fractional distillation, when'y-benzoylprop-yl acetate distils at l10-118 C., at 16 ms, (Analysis:Found: C, 70.0; H, 6.6; C12H1403 requires: C, 70.0; H, 6.8%.)

I claim:

1. Aprocess for the manufacture of keto-alcohol acetates which comprisesheating lactones of the general formula R.C0.0HCO\ CHz--OH in which R isselected from the group consisting of alkyl, aralkyl and aryl groupswith glacial acid in the presence of a substance selected from the groupconsisting of anhydrous sodium acetate and 10 sodium acetate containingacetic acid of crystallisation. r j V 2. A proces for the manufacture of'y-acetopropyl acetate which comprises heating a-aceto- 'y-butyrolactonwith glacial acid in the presence of a substance selected from the groupconsisting of anhydrous sodium acetate and sodium acetate containingacetic acid of crystallisation,

3. A process for the manufacture of 'y-benzoylpropyl acetate whichcomprises heating a-benzoyl- 'y-butyrolactone with glacial acid in thepresence of a substance selected from the group consisting,

ofranhydrous sodium acetate and sodium acetate containing acetic acid ofcrystallisation.

FRANZ BERGEL.

